Marina rates here for a monohull 10-12m bracket, high season, divide by three for Euros:-
90 TND per night all in.
1,100 TND per month plus water and power
3,640 TND Oct-Apr inclusive, plus water and power
5,500 TND Annually.
They will charge the monthly rate rather than the daily rate if it works out cheaper, depending on length of stay.

Ignore the review below. This is a good, well built and maintained marina, with good security, friendly atmosphere and almost empty. There is a warm welcome from the very accommodating staff. I haven’t paid the bill yet but it is about 30 euro a night for an 11m mono.
At the time of writing quarantine consisted of a test after five days’ quarantine. That five days consisted of three days tied up, and the doctor winked and said it took us two days to get here !
The Covid test was 60 euros, same day result, and then the formalities were done. Have a list of unopened booze for customs. No ‘gifts’, or what I call bribes, were requested or given.
The marina is in excellent condition with water and power posts. Not a hint of swell. The showers are fairly good and clean but no laundry. Dry cleaners will do it in town but haggle for a wash, dry and fold, otherwise they charge per item. No lift out facilities.
There is an Italian who does repair work, based in the fish dock. We didn’t need much done so I do not have his name but he would not be difficult to track down. Very disappointed with the result of asking the marina staff about repair work, but that might just be my bad luck.
Wifi is charged separately via a dongle. It is half the price if you get a data-only sim from the Ooredoo (honestly) shop in town, 55TND for 55gig and put it in a spare phone or unlocked dongle. Three TND to a Euro.
Yellow Taxis are very cheap indeed, with meters.
This used to be a French military outpost until a violent revolt by Tunisia against its occupation in the early 1960s. Most locals speak both Arabic and French. It is also reflected in the faded architecture, apart from the ugliest cathedral building I have ever seen, now a cultural centre.
We travel on a strict budget and do not usually eat out but the street food is excellent quality and remarkably cheap (5 euro for two) so we ate out all the time. It is just not worth cooking. Do not go to the Phenicien restaurant. It is terrible. I never seen a waiter smoking over the customers before while leaning on a balcony !
Booze is available from the shuttered off area at the back of Carrefour. A 33cl Heineken is 3TND. Wine isn’t a bad price but only good for cleaning stainless steel. Spirits seemed quite reasonably priced.
The back streets of the old town are seriously Arabian. Narrow, busy, exciting. the fort by the cut into the old port is an experience too. The fish, meat, veg and clothes markets are memorable.
We got ripped off a couple of times, my fault for not doing TND/Euro sums well, but generally everything is startlingly cheap and people very honest. Stock up with spices, herbs, pulses, pasta.
I am indulging my sweet tooth with a 23 cent scoop of ice cream every day. Tomatoes 30 cents a Kg. A huge melon two euro+.
We do not eat lunch but Grille vos Poisson restaurant is across from the Phenicien and its MO is you buy your fish at the market, bring it over, and they cook it and serve with chips, salad or grilled veg for around a Euro or so.
I give Bizerte five stars and is a top spot for stopping the Schengen clock, as well as a heady hit of different culture.